Abstract: The management of agricultural surface source pollution is a key link in promoting the low-carbon transformation and green development of agriculture in China. In order to analyze the important role of high standard basic farmland construction policy in reducing agricultural surface source pollution, this paper attempts to construct a theoretical analysis framework of the impact of high standard basic farmland construction policy on agricultural surface source pollution. The theory was empirically tested using continuous DID model and mediating effect model. The results show that the policy of high standard basic farmland construction has a continuous inhibitory effect on agricultural surface pollution. This conclusion is still valid after replacing the core explanatory variables, placebo test and excluding other policy interference and other robustness tests. "In the physical geography dimension, the "pollution reduction" effect of the policy is significant in the eastern and central regions, but not in the western region. The analysis of the impact mechanism shows that the policy of high standard basic farmland construction can curb agricultural surface pollution through the dual channels of improving land quality and increasing the efficiency of agricultural operation scale. Accordingly, by continuously releasing the policy dividends from the construction of high-standard basic farmland, guiding the large-scale operation of land and accelerating the promotion of green agricultural technology, the two strategic objectives of "reducing pollution" and "increasing production" will be promoted in an integrated manner to achieve sustainable agriculture development in China.